Surgical strategy in treatment of metopic synostosis in a single centre experience: technical note and quantitative analysis of the outcomes.

PURPOSE: Trigonocephaly is the most common craniosynostosis involving orbits. Although some degree of agreement has been reached regarding surgical timing and indications for treatment, there is no consensus regarding the ideal operative technique to guarantee an optimal morphological outcome. The purpose of this study is to describe both strategies and to compare morphological outcomes by means of morphological surface analysis obtained from three-dimensional (3D) stereophotogrammetry, with two different techniques. METHODS: We retrospectively investigated 43 patients with metopic synostosis surgically treated between 2004 and 2020. Two different techniques were applied, addressed as technique A and B. Ten patients undergone postoperative 3d stereophotogrammetry were enrolled, and cephalometric measurements were taken and compared to a cohort of unaffected patients matched by age and gender. RESULTS: Comparison of the groups demonstrated a hypercorrection of the metopic angle of the second technique, associated with a slightly lower correction of the interfrontoparietal diameter. The metopic angle showed to be significantly undercorrected with the first method. CONCLUSIONS: Alternated barrel staving technique appears to be a quick and satisfactory method in cranial remodelling for metopic synostosis. It guarantees an optimal aesthetic result in the first years after surgery.

Piezosurgery in endoscopic-assisted trigonocephaly correction: a technical note.

PURPOSE: This study aims to evaluate the effectiveness of the Piezosurgery® device in endoscopic-assisted correction of trigonocephaly. Trigonocephaly is a type of craniosynostosis characterized by a triangular-shaped forehead due to the premature fusion of the metopic suture. Traditional open cranial vault reconstruction, although common, is invasive and poses risks. The study explores a less invasive alternative using ultrasonic microvibrations for bone cutting, potentially reducing soft tissue damage and improving surgical outcomes. METHODS: The Piezosurgery® device was employed in endoscopic trigonocephaly correction surgeries performed on patients under 4 months old at the French Referral Center for Craniosynostosis in Lyon. The technique involves making a small skin incision and performing osteotomies from the anterior fontanel to the glabella. A rigid 0° endoscope provides visibility, and the Piezosurgery® device enables precise bone cutting while preserving the dura mater. Post-surgery, patients were discharged within 3 days and required to wear a remodeling helmet for 6-8 months. RESULTS: The use of Piezosurgery® device allowed precise osteotomies with minimal soft tissue damage. No dura mater injuries occurred in the patient series. The procedure was efficient, with an average duration of 80 min, and blood loss was minimal, reducing the need for blood transfusions. The endoscopic approach facilitated shorter surgical times and reduced postoperative infection risks. Enhanced visibility during surgery, due to cavitation effects, improved the accuracy of bone cuts. The technique demonstrated promising safety and esthetic outcomes, although it incurred higher costs compared to traditional methods. CONCLUSION: Piezosurgery® device provides a safe and effective method for minimally invasive endoscopic correction of trigonocephaly. The device's ability to selectively cut bone while preserving soft tissues offers significant advantages, despite longer surgical times and higher costs. This technique represents a viable alternative to traditional open surgery, promoting better clinical outcomes and reduced recovery times.

Metopic craniosynostosis: Dynamic cranioplasty for trigonocephaly versus fronto-orbital remodeling and advancement - A retrospective study.

The aim of this study was to compare a traditional fronto-orbital remodeling and advancement (FORA) with the dynamic cranioplasty for trigonocephaly (DCT). The authors analyzed patients who underwent surgery for trigonocephaly. Perioperative data were compared. Parents were asked to use a visual analog scale to evaluate the pre- and postoperative distance between the eyes, the forehead shape, and the global appearance of the face. A panel of observers was asked to grade pre- and postoperative photographs using a similar visual analog scale. Pre- and postoperative anthropometric data were collected and analyzed in a subset of the study population aged 9 years or older. The total sample size was 51 patients (DCT n = 39; FORA n = 12). Durations of surgery and anesthesia were shorter in the DCT group (115 vs 194 min, p = 0.001; 226 vs 289 min, p = 0.001). Patients in the DCT group received similar preoperative ratings to those in the FORA group, but significantly higher postoperative ratings by parents for all three questions. There were no significant differences in postoperative ratings by the panel or postoperative anthropometric data. DCT is safe and effective. It is preferred over FORA because it is associated with shorter durations of surgery and anesthesia, while providing higher degrees of parental satisfaction and similar aesthetic and anthropometric outcomes.

Coexistence of Trigonocephaly and Sylvian Arachnoid Cysts: A Coincidence?

INTRODUCTION: The association between trigonocephaly and Sylvian fissure arachnoid cysts (ACs) has been occasionally reported in the literature. However, the real incidence of this association and its clinical relevance remain unknown. METHODS: The authors collected and retrospectively reviewed all clinical charts and CT scans of patients surgically treated for trigonocephaly at the Pediatric Neurosurgical Department of Fondazione Policlinico Universitario "Agostino Gemelli" IRCCS from January 2014 to June 2023. RESULTS: During the study period, 136 patients with trigonocephaly underwent surgery. Analysis of the clinical charts revealed that in 39.7% of the cases (54/136), preoperative CT scan depicted the presence of a Sylvian fissure AC. Of these, AC was bilateral in 23 cases and unilateral in the remaining 31. All unilateral ACs were on the left side. The ACs were classified as Galassi grade I in 52 cases (96.3%) and Galassi grade II in 2 cases (3.7%). Interestingly, in 1 case we reported a Galassi grade I AC enlargement during follow-up, thereby necessitating surgical fenestration. CONCLUSION: ACs and trigonocephaly are well-known conditions for pediatric neurosurgeons; however, their association is poorly defined. Despite the lack of reports on the incidence and clinical significance of this association, it is worth knowing that radiological follow-up is essential in monitoring AC evolution.

Brain volume in infants with metopic synostosis: Less white matter volume with an accelerated growth pattern in early life.

Metopic synostosis patients are at risk for neurodevelopmental disorders despite a negligible risk of intracranial hypertension. To gain insight into the underlying pathophysiology of metopic synostosis and associated neurodevelopmental disorders, we aimed to investigate brain volumes of non-syndromic metopic synostosis patients using preoperative MRI brain scans. MRI brain scans were processed with HyperDenseNet to calculate total intracranial volume (TIV), total brain volume (TBV), total grey matter volume (TGMV), total white matter volume (TWMV) and total cerebrospinal fluid volume (TCBFV). We compared global brain volumes of patients with controls corrected for age and sex using linear regression. Lobe-specific grey matter volumes were assessed in secondary analyses. We included 45 metopic synostosis patients and 14 controls (median age at MRI 0.56 years [IQR 0.36] and 1.1 years [IQR 0.47], respectively). We found no significant differences in TIV, TBV, TGMV or TCBFV in patients compared to controls. TWMV was significantly smaller in patients (-62,233 mm3 [95% CI = -96,968; -27,498], Holm-corrected p = 0.004), and raw data show an accelerated growth pattern of white matter in metopic synostosis patients. Grey matter volume analyses per lobe indicated increased cingulate (1378 mm3 [95% CI = 402; 2355]) and temporal grey matter (4747 [95% CI = 178; 9317]) volumes in patients compared to controls. To conclude, we found smaller TWMV with an accelerated white matter growth pattern in metopic synostosis patients, similar to white matter growth patterns seen in autism. TIV, TBV, TGMV and TCBFV were comparable in patients and controls. Secondary analyses suggest larger cingulate and temporal lobe volumes. These findings suggest a generalized intrinsic brain anomaly in the pathophysiology of neurodevelopmental disorders associated with metopic synostosis.

Clomiphene Citrate and Enclomiphene Hydrochloride Exposure Is Associated With Interfrontal Suture Fusion in Zebrafish.

Background: The last several decades have witnessed an increase in metopic craniosynostosis incidence. Population-based studies suggest that pharmacological exposure in utero may be responsible. This study examined effects of the fertility drug clomiphene citrate (CC) on calvarial development in an established model for craniofacial development, the zebrafish Danio rerio. Results: Zebrafish larvae were exposed to clomiphene citrate or its isomer enclomiphene for five days at key points during calvarial development. Larvae were then raised to adulthood in normal rearing water. Zebrafish were analyzed using whole-mount skeletal staining. We observed differential effects on survivability, growth and suture formation depending on the treatment. Treatments with CC or enclomiphene at 5.5 mm SL led to increased fusion of the interfrontal suture (p < .01) compared to controls. Conclusions: Exposure to fertility drugs appears to affect development of the cranial vault, specifically the interfrontal suture, in zebrafish. Further research is required to identify the signaling mechanisms at play. This work suggests that fertility drug treatment may contribute to the increased incidence of metopic craniosynostosis observed globally.

Historique : L'incidence de craniosynostoses métopiques a augmenté ces dernières décennies. D'après les études en population, l'exposition aux médicaments in utero pourrait en être responsable. La présente étude traite des effets d'un agent ovulatoire, le citrate de clomifène (CC), sur le développement de la voûte crânienne d'un modèle établi de développement crâniofacial, le poisson-zèbre Danio rerio. Résultats : Les chercheurs ont exposé des larves de poisson-zèbre au citrate de clomifène ou à son isomère, l'enclomiphène, sur une période de cinq jours à des moments clés du développement de la voûte crânienne. Ils les ont ensuite élevés jusqu'à l'âge adulte dans de l'eau normale. Ils ont analysé les poissons-zèbres par coloration du squelette entier et observé des effets différentiels sur la capacité de survie, la croissance et la formation des sutures en fonction du traitement. Les traitements au CC ou à l'enclomiphène d'une longueur standard de 5,5 mm ont entraîné une fusion accrue de la suture métopique (p < 0,01) par rapport aux sujets témoins. Conclusions : L'exposition aux agents ovulatoires semble influer sur le développement de la voûte crânienne, notamment la suture métopique, chez le poisson-zèbre. D'autres recherches devront être réalisées pour déterminer les mécanismes de signalisation en jeu. Selon la présente étude, les agents ovulatoires peuvent contribuer à l'incidence accrue de craniosynostose métopique sur la scène mondiale.

The Use of Artificial Intelligence for the Classification of Craniofacial Deformities.

Positional cranial deformities are a common finding in toddlers, yet differentiation from craniosynostosis can be challenging. The aim of this study was to train convolutional neural networks (CNNs) to classify craniofacial deformities based on 2D images generated using photogrammetry as a radiation-free imaging technique. A total of 487 patients with photogrammetry scans were included in this retrospective cohort study: children with craniosynostosis (n = 227), positional deformities (n = 206), and healthy children (n = 54). Three two-dimensional images were extracted from each photogrammetry scan. The datasets were divided into training, validation, and test sets. During the training, fine-tuned ResNet-152s were utilized. The performance was quantified using tenfold cross-validation. For the detection of craniosynostosis, sensitivity was at 0.94 with a specificity of 0.85. Regarding the differentiation of the five existing classes (trigonocephaly, scaphocephaly, positional plagiocephaly left, positional plagiocephaly right, and healthy), sensitivity ranged from 0.45 (positional plagiocephaly left) to 0.95 (scaphocephaly) and specificity ranged from 0.87 (positional plagiocephaly right) to 0.97 (scaphocephaly). We present a CNN-based approach to classify craniofacial deformities on two-dimensional images with promising results. A larger dataset would be required to identify rarer forms of craniosynostosis as well. The chosen 2D approach enables future applications for digital cameras or smartphones.

Natural history of mild trigonocephalic deformities.

OBJECTIVE: Ridging along the metopic suture line can be a common cause of concern for parents and has been theorized to represent a mild form of trigonocephaly, a cranial deformity associated with risks of negative cosmetic outcomes, if not surgically corrected. Yet the literature contains sparse reports of long-term cosmetic results or expectations for infants with isolated metopic ridging compared with those with severe trigonocephaly, or even what objective metrics discriminate isolated metopic ridging from severe trigonocephaly. Therefore, the authors' goals for this study were to 1) quantify the degree of frontal deformity among patients with metopic ridge, metopic craniosynostosis, and normocephalic head shapes; and 2) document the natural history of frontal deformities in isolated metopic ridge patients in the 1st year of life. METHODS: This was a retrospective cohort study of patients with normocephalic head shapes, metopic ridges, and metopic craniosynostoses who presented at < 1 year of age to the Connecticut Children's neurosurgery clinic from January 2019 to December 2021. Data were collected regarding demographics and photograph-based craniometrics. RESULTS: A total of 212 normocephalic, 34 metopic ridge, and 29 metopic craniosynostosis patients were included. Both the normocephalic and metopic ridge groups had a significantly higher anterior arc angle (AAA) value compared with the metopic craniosynostosis group (p < 0.0001). The AAA did not differ significantly among normocephalic patients and those with ridging. Over the course of 1 year of follow-up, patients with metopic ridging demonstrated a slight decrease in AAA values, but overall remained within the same range as normocephalic patients. CONCLUSIONS: Photograph-based craniometrics suggest that metopic ridge patients with frontal bone angulations > 2.2 radians have a mild degree of frontal constriction that does not significantly worsen over the 1st year of life.

Assessing craniofacial growth and form without landmarks: A new automatic approach based on spectral methods.

We present a novel method for the morphometric analysis of series of 3D shapes, and demonstrate its relevance for the detection and quantification of two craniofacial anomalies: trigonocephaly and metopic ridges, using CT-scans of young children. Our approach is fully automatic, and does not rely on manual landmark placement and annotations. Our approach furthermore allows to differentiate shape classes, enabling successful differential diagnosis between trigonocephaly and metopic ridges, two related conditions characterized by triangular foreheads. These results were obtained using recent developments in automatic nonrigid 3D shape correspondence methods and specifically spectral approaches based on the functional map framework. Our method can capture local changes in geometric structure, in contrast to methods based, for instance, on global shape descriptors. As such, our approach allows to perform automatic shape classification and provides visual feedback on shape regions associated with different classes of deformations. The flexibility and generality of our approach paves the way for the application of spectral methods in quantitative medicine.

Metopic ridge presenting to pediatric dermatology and vascular anomalies clinics.

Metopic ridge (MeR) is a midline osseous forehead prominence resulting from physiologic closure of the underlying metopic suture. This mass-like ridge can be mistaken for serious conditions such as a craniosynostosis or vascular anomaly, prompting concern and workup. We reviewed patients presenting for a forehead mass to Vascular Anomalies and Dermatology clinics and diagnosed with MeR to increase familiarity with this finding and to encourage MeR in the differential diagnosis of pediatric midline forehead masses.

Is endoscope-assisted strip craniectomy the future of metopic suture craniosynostosis treatment? An 11-year experience with 62 patients.

OBJECTIVE: Endoscopic mini-invasive treatment for sporadic trigonocephaly is becoming a widely accepted surgical treatment. In most centers this treatment is performed in association with postoperative helmeting. The aim of the present study was to review and report the authors' 11-year experience of endoscope-assisted metopic suturectomy for treatment of 62 trigonocephaly patients without helmet use. METHODS: For this retrospective study, clinical data of 62 consecutive pediatric patients (age 3-8 months) were obtained from the data bank of the "Anna Meyer" Children Hospital. These patients had been diagnosed with trigonocephaly (type II and III) and undergone surgery performed with a mini-invasive endoscopic technique during the period from January 2011 to January 2022. No helmet was used postoperatively in these patients, and they were evaluated through craniometric measurements, pre-/postoperative photographs, and parents' impressions, as well as thorough clinical examinations during follow-up appointments. RESULTS: The mean patient follow-up period was 6 ± 1.3 years. The female/male ratio was 1:2; 52% of the patients presented with type II trigonocephaly and the remaining patients with type III. The mean age at surgery was 153 ± 44 days (5 ± 1.5 months, range 3-8 months). In 92% of the patients the surgical outcome was defined as good to excellent. However, 4 patients presented with an unsatisfactory outcome, including 1 patient with a CSF collection requiring surgical repair 2 months after the first surgery and 1 patient who developed infection of the surgical wound and needed a second surgery. In the latter patient the outcome was evaluated as satisfactory, and no sequelae regarding the infection were encountered during follow-up. CONCLUSIONS: According to the authors' experience, endoscopic metopic suturectomy alone, without the use of a helmet, is a valid surgical option for trigonocephaly treatment, and its application can be considered in patients of older age groups (up to 8 months). Thus, in the right patient selection context, this technique represents the treatment of choice.

A Three-Dimensional-Based Morphometric Analysis of a Standardized Overcorrection Technique for Fronto-Orbital Advancement in Metopic Craniosynostosis.

INTRODUCTION: The concept of "overcorrection" for trigonocephaly has been reported to achieve both anterior cranial fossa expansion and normalization of craniofacial form. The purpose of this study is to describe in detail a standardized technique to fronto-orbital advancement utilizing the concept of "overcorrection" and objectively evaluate intermediate results. METHODS: This retrospective study included patients with isolated metopic synostosis who underwent surgery via the proposed surgical technique and age and sex-matched unaffected controls. Craniofacial morphometric analysis was performed on pre-, immediate post-, and intermediate postoperative (>2 years) three-dimensional (3D)-rendered computed tomographic (CT) scans and photographs. Key CT-based measurements included interzygomaticofrontal suture distance (IZFS), endocranial bifrontal angle (ECA), and temporal expansion. 3D photogrammetry was performed using established measurements and associated Z-scores converted. A Paired t-test and analysis of variance were performed when appropriate. RESULTS: Forty-one patients were included. A comparison of pre- and immediate postoperative CT scans demonstrated statistically significant increases in all measurements. Subset analysis of 12 patients with intermediate follow-up (age: 39.6 ± 3.6 months) demonstrated significant differences from preoperative values except for IZFS, which decreased from immediate postoperative values and was smaller than age- and sex-matched controls. 3D photogrammetry demonstrated a mean Z-score above the norm for frontal breath. 3D photogrammetry is also positively correlated with CT-based measurements. CONCLUSIONS: This standardized "overcorrection" approach for trigonocephaly can provide the appropriate changes to maintain a normal ECA despite a reduction in bifrontal width over time. 3D photogrammetry positively correlated with CT-based measurements and may provide useful information when following patients clinically. Long-term follow-up assessment to determine the necessary degree of overcorrection at skeletal mature is needed.

Impact of age at endoscopic metopic synostosis repair on anthropometric outcomes.

OBJECTIVE: Endoscopic strip craniectomy for metopic craniosynostosis relies on rapid growth and postoperative helmeting for correction. Endoscopic repair is generally performed before patients reach 4 months of age, and outcomes in older patients have yet to be quantified. Here, the authors examined a cohort of patients treated with endoscopic repair before or after 4 months of age to determine aesthetic outcomes of delayed repairs. METHODS: Data from eligible patients were retrospectively assessed and aggregated in a dedicated metopic synostosis database. Inclusion criteria were radiographically confirmed metopic synostosis and endoscopic treatment. Patients were dichotomized into two groups: those younger than 4 months and those 4 months or older at the time of repair. The frontal width and interfrontal divergence angle (IFDA) were measured on reconstructed CT images. These measurements, alongside operative time, estimated blood loss, and transfusion rates, were compared between groups using the Student t-test or chi-square test. RESULTS: The study population comprised 28 patients treated before 4 months of age and 8 patients treated at 4-6 months of age. Patient sex and perioperative complications did not differ by age group. Older age at repair was not significantly associated with 1-year postoperative IFDA (140° ± 4.2° vs 142° ± 5.0°, p = 0.28) or frontal width (84 ± 5.2 vs 83 ± 4.4 mm, p = 0.47). CONCLUSIONS: One-year postoperative IFDA and frontal width do not differ significantly between patients treated before and after 4 months of age. Further study with longer follow-up is necessary to confirm the longevity of these results at skeletal maturity.

Management of Unicoronal and Metopic Synostoses: Minimally Invasive Approaches.

Early endoscopic-assisted correction of unicoronal and metopic synostosis is an excellent, safe, cost-effective, and highly effective option for affected patients. Although open calvarial remodeling has a place in the armamentarium of the craniofacial team, the skull base changes seen in endoscopic-assisted techniques are unparalleled. The procedures are associated with low morbidity and no mortality. There is minimal blood loss, decreased operating time, significantly reduced blood transfusion rates, decreased hospitalization length, decreased cost, and less pain and swelling. Early diagnosis and referral for surgical evaluation are critical to obtaining these results.

Trigonocephaly: Quantitative Comparison of the Complete Vault Reconstruction and Minimally Invasive Suturectomy.

OBJECTIVE: The objective of the study was to present and compare outcomes and complications of conventional open reconstruction and minimally invasive correction of metopic synostosis in patients who underwent treatment of trigonocephaly in our center between 2015 and 2019. METHODS: The hospital database was searched for hospitalization and surgical information, as well as imaging of individuals with trigonocephaly. Postoperative evaluation of the patients was performed during the follow-up sessions. The radiological evaluation was based on brain computed tomography scans taken 2 years following the operation. RESULTS: Sixty-four patients (19 females and 45 males) had their trigonocephaly corrected surgically. Thirty-five patients (9 females and 26 males) had complete vault reconstruction surgery, while 29 patients (10 females and 19 males) had minimally invasive suturectomy (MIS). The postoperative cephalic width/intercoronal distance ratio and interpupillary distance/interfrontozygomatic distance ratio assessment showed no differences in the outcome of both groups (P value > 0.05). Minimally invasive techniques resulted in less intraoperative bleeding, a shorter stay in the intensive care unit and hospital, and a shorter surgery and anesthesia duration (P value < 0.05). CONCLUSIONS: Surgical treatment of trigonocephaly can result in a satisfactory correction of the deformity. MIS delivers a comparable result to complete vault reconstruction with less invasiveness and hospitalization and can be considered a reasonable option for patients in their early months of life. Patients must, however, undergo long-term cosmetic, behavioral, and developmental evaluations.

A Diffusion Tensor Imaging Analysis of Frontal Lobe White Matter Microstructure in Trigonocephaly Patients.

BACKGROUND: Children with trigonocephaly are at risk for neurodevelopmental disorders. The aim of this study is to investigate white matter properties of the frontal lobes in young, unoperated patients with metopic synostosis as compared to healthy controls using diffusion tension imaging (DTI). METHODS: Preoperative DTI data sets of 46 patients with trigonocephaly with a median age of 0.49 (interquartile range: 0.38) years were compared with 21 controls with a median age of 1.44 (0.98) years. White matter metrics of the tracts in the frontal lobe were calculated using FMRIB Software Library (FSL). The mean value of tract-specific fractional anisotropy (FA) and mean diffusivity (MD) were estimated for each subject and compared to healthy controls. By linear regression, FA and MD values per tract were assessed by trigonocephaly, sex, and age. RESULTS: The mean FA and MD values in the frontal lobe tracts of untreated trigonocephaly patients, younger than 3 years, were not significantly different in comparison to controls, where age showed to be a significant associated factor. CONCLUSIONS: Microstructural parameters of white matter tracts of the frontal lobe of patients with trigonocephaly are comparable to those of controls aged 0-3 years.

Correction of trigonocephaly after endoscopic strip craniectomy with postoperative helmet orthosis therapy: a 3D stereophotogrammetric study.

OBJECTIVE: Endoscopic strip craniectomy with postoperative helmet orthosis therapy (ESCH) has emerged as a less invasive alternative to fronto-orbital remodeling for correction of trigonocephaly. However, there is no standardized objective method for monitoring morphological changes following ESCH. Such a method should be reproducible and avoid the use of ionizing radiation and general anesthesia for diagnostic imaging. The authors analyzed a number of metrics measured using 3D stereophotogrammetry (3DSPG) following ESCH, an imaging alternative that is free of ionizing radiation and can be performed on awake children. METHODS: 3DSPG images obtained at two time points (perisurgical and 1-year follow-up [FU]) of children with metopic synostosis who had undergone ESCH were analyzed and compared to 3DSPG images of age-matched control children without craniofacial anomalies. In total, 9 parameters were measured, the frontal angle and anteroposterior volume in addition to 7 novel parameters: anteroposterior area ratio, anteroposterior width ratios 1 and 2, and right and left anteroposterior diagonal ratios 30 and 60. RESULTS: Six eligible patients were identified in the operated group, and 15 children were in the control group. All 9 parameters differed significantly between perisurgical and age-matched controls, as well as from perisurgical to FU scans. Comparison of FU scans of metopic synostosis patients who underwent surgery to scans of age-matched controls without metopic synostosis revealed that all parameters were statistically identical, with the exception of the right anteroposterior diagonal ratio 30, which was not fully corrected in the treated patients. The left anterior part of the head showed the most change in surface area maps. CONCLUSIONS: In this pilot study, ESCH showed satisfactory results at 1 year, with improvements in all measured parameters compared to perisurgical results and normalization of 8 of 9 parameters compared to an age-matched control group. The results indicate that these parameters may be useful for craniofacial units for monitoring changes in head shape after ESCH for trigonocephaly and that 3DSPG, which avoids the use of anesthesia and ionizing radiation, is a satisfactory monitoring method.

Finite element method for the design of implants for temporal hollowing.

Temporal indentations are the most impacting craniofacial complication after coronal flap dissection. It is mainly due to a temporal fat pad or temporalis muscle dissection. Because of the great improvements achieved recently in CAD-CAM-aided surgery and the possibility of performing accurate pre-surgical virtual planning, it is now possible to correct it with a customised virtual approach. Furthermore, advancements in material science have allowed surgeons to rely on biocompatible materials like PEEK (showing a low complication and recurrence rate) for the manufacturing of patient-specific implants. We hereby describe our experience on a case of secondary and corrective surgery after a fronto-orbital remodelling, in which we used PEEK implants designed by CAD and optimized by finite element modelling.

The use of a single-piece bone flap for cranial reshaping in anterior craniosynostosis patients: clinical experience and a description of a novel technique.

BACKGROUND: Craniosynostosis is known as premature closure of one or more of the cranial sutures. Anterior craniosynostosis involves anterior plagiocephaly and trigonocephaly. One of the issues in anterior craniosynostosis skull reshaping is maintaining an aesthetically pleasing forehead curve. Therefore, in this article, we demonstrate our novel technique to use a single-piece bone flap for cranial reshaping of the anterior mold in patients diagnosed with anterior craniosynostosis. A retrospective record review of patients who underwent single piece bone flap cranial reshaping for correction of unicoronal synostosis (UCS) and metopic synostosis (MS) at an Academic Institute in Riyadh, Saudi Arabia, between 2018 and 2020, was conducted. RESULTS: Six non-syndromic consecutive patients were included. Three of the patients had MS. The mean age at surgery was 11.16 months (range, 6-19 months). The average OR time was 315 min (range, 263-368 min). The average intraoperative blood loss was 225 ml (range, 100-400 ml). All patients had achieved acceptable functional and aesthetic results. CONCLUSION: Our novel technique is an innovative and efficient reconstructive technique to simultaneously address MS and UCS and minimize intraoperative bleeding and surgery time. However, more studies with more cases are required.

Intracranial Volume Not Correlated With Severity in Trigonocephaly.

OBJECTIVES: Severity of trigonocephaly varies and potentially affects intracranial volume (ICV) and intracranial pressure (ICP). The aim of this study is to measure ICV in trigonocephaly patients and compare it to normative data and correlate ICV with the severity of the skull deformity according to UCSQ (Utrecht Cranial Shape Quantifier). DESIGN: Retrospective study. SETTING: Primary craniofacial center. PATIENTS, PARTICIPANTS: Nineteen preoperative patients with nonsyndromic trigonocephaly (age ≤12 months). INTERVENTION: Intracranial volume was measured on preoperative computed tomography (CT) scans by manual segmentation (OsiriX Fondation). Utrecht Cranial Shape Quantifier was used to quantify the severity of the skull deformity. When present, papilledema as sign of elevated ICP was noted. MAIN OUTCOME MEASURES(S): Measured ICV was compared to Lichtenberg normative cranial volume growth curves, and Pearson correlation coefficient was used to correlate UCSQ with the ICV. RESULTS: Mean age at CT scan was 6 months (2-11). Mean measured ICV was 842 mL (579-1124). Thirteen of h19 patients (11/15 boys and 2/4 girls) had an ICV between ±2 SD curves of Lichtenberg, 2 of 19 (1/15 boys and 1/4 girls) had an ICV less than -2 SD and 4 of 19 (3/15 boys and 1/4 girls) had an ICV greater than +2 SD. Mean UCSQ severity of trigonocephaly was 2.40 (-622.65 to 1279.75). Correlation between severity and ICV was negligible (r = -0.11). No papilledema was reported. CONCLUSIONS: Measured ICV was within normal ranges for trigonocephaly patients, in both mild and severe cases. No correlation was found between severity of trigonocephaly and ICV.